Industry's Hot Topic: Fundamentals of Combustible Dusts

Since the Standards Council approval to enter into a revision cycle, the NFPA 652, Standard on Combustible Dusts, draft entered into revision cycle, Fall 2014, and was open for Public Input (PI).  Now that the closing date has past, we finally tallied the number of PIs for NFPA 652. The final count is 470 PIs!

To receive this much input reminds us the impact that the document will have on the industry. It also shows how involved the industry is with our standards development process. Having the industry involved at the birth of a new standard is great as it will only strengthen the docuemnt and make it more applicable to the "real world". The Technical Committee (TC) meets at NFPA in a month (February 12-14) for an exciting First Draft Meeting.

Comments

[Venkateswara Sarma Bhamidipati]

1 We should clearly work out a way to classify combustible dusts and non combustible dust with addtional information. Not just Kst/Pmax alone. For eg. Milk Powder and Sulfur have same range of Kst/PMax. Is it justified? May be new class which takes into account of MIE also?

2. What is the reason for using Chemical Igniters as against Electric arc in ASTM-1226.

Can this test be used in using A/B explosion classification (like in ATEX draft std)? does that use electric spark?

We have seen that commercial Kst test labs use 2 x 5 KJ chemical in 20 Lt vessel. Is it not overdriving the results?

Why they do not use electrical arc and if this helps in ruling out some dusts as non-combustible and exclude as B class

We should also highlight and distinguish the differences between electric arc/chemical igniters in triggering explosion

[Derek Duval]

Venkateswara Bhamidipati,

Thank you for your comment. You can review the preliminary draft and follow along with the development of this new standard here www.nfpa.org/652. You second question seems to be more geared toward the ASTM testing and not the NFPA standard. You can also submit any comments you have to the development of this document starting in September.